For convenience purposes, it is well known to provide garage doors which utilize a motor to provide opening and closing movements of the door. Motors may also be coupled with other types of movable barriers such as gates, windows, retractable overhangs and the like. An operator is employed to control the motor and related functions with respect to the door. It is also known to provide safety devices that are connected to the operator for the purpose of detecting an obstruction so that the operator may then take corrective action with the motor to avoid entrapment of the obstruction.
There are three basic types of transmitters that can be used to instruct an operator to initiate a desired action. A portable or remote transmitter is usually kept in the user's vehicle and allows the user to open and close the door from inside the vehicle. The portable transmitter may have several buttons, wherein each button is associated with operation of a different door. A wall station transmitter is usually mounted near an interior door of the garage and allows the user to open and close the garage door as needed. The wall station may include function buttons to allow programming of the operator, delay closing of the door, setting of a pet height and other functions. The other type of transmitter is a keypad, which is typically mounted outside the garage, that requires manual entry of a code prior to sending an open/close signal. These remote devices may also be provided with additional features such as the ability to control multiple doors, lights associated with the doors, and other security features.
In order for a transmitter device to work with an operator to control movement of the garage door, the operator must be programmed to learn the particular serial number code for each transmitter. In the past, radio controls utilized a code setable switch, such as a ten-circuit DIP switch to set the data for both the transmitter and the receiver. Both the transmitter and the receiver's code switch must match for the transmitter to activate the receiver's output. This method did not allow for enough unique codes and was relatively easy for someone to copy the code and gain improper access. Accordingly, this process required the setting of transmitter and receiver codes physically switched to identical settings for operation of the garage door.
Presently, most radio controls for garage doors use either a fixed code format wherein the same data for each transmission is sent, or a rolling-code format, wherein some or all of the data changes for each transmission. A fixed code transmitter, also known as a fixed address or a fixed serial number transmitter, is assigned and factory programmed into a transmitter's non-volatile memory during the manufacturing of the product. A receiver is designed to “learn” a transmitter's code and the transmitter's code is stored in the receiver's non-volatile memory. This increased the number of possible codes (from 1024 or 19,683 to millions) and eliminated the DIP switch. This also prevented the code from being visible, as is the case with the DIP switch transmitter, thus preventing theft of the code.
A rolling code transmitter is similar to a fixed code transmitter, but at least a portion of the address, also known as the code or serial number, is changed with every operation of the transmitter. The transmitter and the corresponding receiving unit use an algorithm to determine what the next code to transmit/receive shall be. Only the proper code will activate the receiver.
The use of the portable or remote transmitter is problematic inasmuch as it provides ready access to a home or business if the remote transmitter falls into the wrong hands. For example, an opportunistic thief may steal just the remote transmitter from an automobile, and knowing where that person lives can, at a time when the home or business owner is absent, use the remote transmitter to enter the site and perform whatever mischief. The only known solution to this problem is to clear all transmitter codes from the operator and then re-learn the transmitters so that different codes activate the operator and move the barrier. This is time consuming and, if not done properly, still may allow the stolen transmitter to be used with the operator. Therefore, there is a need in the art to provide a remote transmitter that allows for use in an unsecure, single button actuation mode, or a secure, multiple button actuation mode.